Preparation of hydroxyalkyl esters of the dicarboxylic acid esters of cellulose and the products resulting therefrom



Patented Aug. 18, 1936 um- ED" PREPARATION OF HYDROXYALKYL ESTERS I OFTHE DICARBOXYLIC ACID ESTERS OF CELLULOSE wAND THE PRODUCTS SULTINGTHEREFROM Carl J. Malm and Charles R. Fordyce, Rochester, N. Y.,assignors to Eastman Kodak Company,

Rochester, N. Y., a corporation of New York No Drawing. ApplicationSeptember 23, 1933,

Serial No. 690,762

7 '15 Claims. .(Cl. 260-101) The present invention relates to thepreparation of a hydroxyalkyl ester of a dicarboxylic acid ester ofcellulose by reacting upon the cellulose ester or its'salt with analkylene oxide.

Heretoforethe reaction betweencellulose itself and analkylene oxide hasbeen accomplished; however, in that case it has been'necessary to usecaustic alkali, the action of which is degrading upon the cellulose. Inthat case, also, in addition to the cellulose being degraded, th e groupadded by the alkylene oxide is attached to the cellulose itself so thatthe res'ulting product is of the cellulose" ether type; e

One object of our invention is to provide a process of, incorporatinghydroxyalkyl groups by means of an alkylene. oxide into a cellulosederivative without any danger of degrading the cellulose. Another objectof our invention is to provide a process of esterii'ying the carboxyluncombined with'thecellulose in a dicarboxylic acid ester of cellulose.Other objectswill appear herein. 1 t f We have found that if adicarboxylic acid ester of cellulose or itssaltistreatedwith an alkyleneoxide, a hydroxy alky ester of the 'dicarboxylic acid ester of celluloseis formed. The starting material may either bea simple dicarboxylic acidester or .it maybe a mixed ester inwhich. either some or all of theacylgroupsmay be dicarboxylic.

The preparation of the cellulose esters and their salts, which may beemployed as the starting material of the .presentprocess is disclosedbroadly in Malm and Waring application Serial No. 380,252, filed July22, 1929. These esters are prepared by treating cellulose or anesterifiable cellulose derivative, such :asaa cellulose acetate or acellulose ether such as ethyl cellulose having esterifiable hydroxylgroups with a dicarboxylic anhydride, such as phthalic, in the presenceof an organic base, such as pyridine, which results' in the pyridinesalt of the dicarboxylic acid ester of cellulose. To form the ester withfree carboxyl proper treatment with a dilute acid is employed to removethe pyridine. The salts may be prepared-by treating the estercontain-ing thefree carboxyl with a-wat'er-soluble" hydroxide-such asthat of sodium. The cellulose-esters, which may be employed as thestarting material, may be the esters of phthalic acid such as aredisclosed and claimed in Malm and Waring application Serial No. 380,2 2,the esters of succinic acid such as are disclosed and claimed in Malmand Waring application Serial No. 627,150, filed July 30, 1932, or theesters of diglycollic acid such as are disclosed and claimed in Malm andFordyce application Serial No;,62',7,l47,- filed July 30,1932. Any ofthe .salts of the dicarboxylic acid esters of cellulose, especiallythose of the alkali metals such as are disclosed in Malm and Waringapplication Serial N0. 627,149, filed July '30, 1932, be

ployed as the starting material of a process in..'ac-' cordance with thepresent invention. V

The reaction in accordancewith the present invention appears to becharacteristic of the alkylene oxides in general as in every instance inwhich processes have been carried out in accordance with the presentinvention the process has proceeded in the manner'described. In view ofthe fact that the lower members of this series, such as the oxides ofethylene, propylene .and butylene, are the more common and have greaterreactivity, their use is preferredin the present process.

The following examples embodying our invention:

Example I allowed to standwithout heating for a number illustrateprocesses oi" days. It is then diluted with acetone and precipitatedin alarge volumeof water, where? upon the resulting product is Washed anddried. The cellulose acetate beta hydroxy propyl phthalate prepared inaccordance with the above procedure contains 6.1% free phthalyl ascompared to 33% in" the original material. It is solublein' acetone,methyl acetate, ethylene chloride-alcohol (4:1) and benzene-alcohol(2:1).

Example 11;

10 lbs. of celluloseacetate phthalatehaving a phthalyl content of 33%are dissolved i n lbs. of propylene oxide and the mixture is al-' ilwed; to; stand; atroom temperature i ora ber of. weeks, :T e solutiqniat en rsli llt dwith acetone andpre ioitate in. :1 seprq l ms 9 waterwhereupon the resulting duct, is wasl ed and dried. The celluloseacetate beta hydroxy propyl phthalate prepared in accordance with writs.of cellulo e. ph hala ei inss htha .dcontent. Qi';5D.% are mix d ;W t. ldioxanfindizll l 1 pro vlqn vqxi ls @Ill $116: mix- .tureisrefluxedfQI;. h EQ 8'5. cellulose pht t 1 atfirstinwluhs h 1 -.action mi ture bu,arter being: heated 9 l i bath.- The chloroform, ,benzenefew minutes,beg ns to Swen and partially into" perature for several days, or untilan insoluble j ell fis formed. This jell is dissolved in acetone and Isolution: -After a few "hours, completesolution takes place The mixtureis then precipitated in: i a large volume of water and the cellulosehydroxy 1 propyl phthalate formed 'is'" washed and dried;

Upon analysis, it exhibits a free phthalyl content 0f 1 6%. H

V Example'IV lbs. of a sodiumsalt'ofa cellulose acetate phthalate aredissolved in 3 gals. of water and 10 f lbs. of ethylene oxide arestirred into the solution,

and the whole is allowed to stand at room temprecipitated in diluteacetic acid." -The product formedis'veryjsimilar to that formed inExamples 1 and II above. E

The reaction which appears to take place in, for instanceQ'Example I mayberepresented as follows;

represents a unit of cellulose and Ac'represents' acyl groups, such asacetyl, propionyl, butyryl or the like. Obviously thephthalyl contentmay difier from that shown. When ethylene oxide is employed, thereaction may be represented as When an: aliphatic dicarboxylic acidester of cellulose; such as a. succinate is employed,'the reaction whichappears to take place may be represented as follows: r

; It is to' be understood that where the term dicarboxylic acid esterlofcellulose is employed 'herein,-'-'it refers-to either those esters inwhich the second carboxyl of the dicarboxylic acid radical isunesterified or tothe salts of those esters.

The structural"formulaeherein are illustrative 5 and are to beunderstoodas not restrictive'as to containing dicarboxyl and other theproportions of the groups'or radicals present in thecompoundrepresented.

a What we claim as our invention is: 1. A process of preparing a hydroxyaliphatic ester of a dicarboxylic acid ester of cellulose whichcomprises reacting upon the dicarboxylic o acid ester of cellulose withan alkylene'oxide.

2. A process of preparing a hydroxy aliphatic .esterof a 'dicarboxylicacid ester of. cellulose which comprises reacting upon a cellulose estercontaining dicarboxyl 'and other acyl groups with an alkylene oxide.v

- 3. A process of preparing a hydroxy ali'phatic ester ofa phthalic acidester of cellulose which comprises reacting upon the phthalic acid esterwith an'alkylene oxide I 4.,A process of preparing} hydroxy aliphaticlene oxide; V

5. A process of preparing a hydroxy propyl 'ester of a dicarboxylic acidester of cellulose which comprises reacting upon'the dicarboxylic acidester of cellulose with propyleneoxide.

6. A' process of preparing a hydroxy propyl ester of a dicarboxylic acidester of, cellulose I ester of a phthalic acid esterot cellulose whichcomprises reacting upon a cellulose ester containe ing phthalyl andother acyl groups with an alky' which comprises reacting uponjacelluloseester propylene oxide.

'7. A process of 'preparing'a hydroxy propyl ester of a phthalicacidester of cellulose which.

of a dicarboxylic acid ester ofcellulose which a comprises reacting uponthe dicarboxylicjacid f ester of cellulose with ethylene oxide.

10. The cellulose compound represented byfthe representsa Cs unit ofcellulose,-Arepresents either H,jan acyl, an alkyl or an Beak-0-4!. p/ js group, R represents either H or an alkyl radical and R1 representseither'an. alkyl or an 'aryl group. V V V 11. A hydroxy aliphatic esterof a dicarboxylic 14. A hydroxy propyl ester of a phthalic acid acidester of cellulose. ester of cellulose.

12. A hydroxy propyl ester of a. dicarboxylic 15. A hydroxy ethyl esterof a dicarboxylic acid acid ester of cellulose. ester of cellulose. 513. A hydroxy aliphatic ester of a, phthalic acid. CARL J. MALM.

ester of cellulose. CHARLES R. FORDYCE.

